Conventionally, when digital contents such as an HTML file distributed by using data communications through the digital data broadcasting or the Internet is printed by the printer, the layout information of one page is divided into plural bands. A drawing process for each band is performed. That is, a rendering process for converting an object included in each band into the drawing data is performed.
This is because a printer having insufficient memory capacity can not hold the drawing data of one page at any time. In this case, it is required to perform a process for converting the object included in the area of band to be drawn into the drawing data by referring to the object from the printer side (external reference process). In such an external reference process, the printer analyzes the contents described in the input HTML file, and acquires an address at which the object such as image data is actually stored. And it accesses a device corresponding to the address and acquires the object such as image data.
Therefore, when the same object covers plural bands, the printer is required to make the external reference to the same object many times, every time the drawing process for each band is performed. Consequently, the print processing time is longer, and the drawing efficiency is worse.
On the contrary, there is a technology in which the band height is temporarily decided to set an initial value for every band sequentially, the total sum of object drawing areas within the height is calculated, and the band height is adjusted to be a preset threshold or less sequentially (U.S. Pat. No. 6,542,255).
However, the above-mentioned technology of U.S. Pat. No. 6,542,255 does not decrease the frequency at which the object is externally referenced. In this prior technical document, a technology is disclosed in which it is judged whether or not a figure takes long time for processing, and for the figure that takes long time for processing, a band of the minimum height containing its drawing range is set to improve the processing efficiency. However, with the constitution of achieving the technology concerned, it is not possible to decrease the frequency at which the object is externally referenced, because the object of graphic or text to be processed relatively simply may continue to extend over plural bands.
For instance, in the case of analyzing a structured document data and dividing the layout information of one page obtained into plural bands to make the drawing, if an object extending over plural bands appears, not only the band dividing process becomes complex, but also the drawing efficiency is lower because external reference to the same object occurs every time. Especially when the address of the object is one of an external apparatus via a network, for example, the Internet, the drawing efficiency is remarkably worse.
Generally, in the digital television, and recently the portable equipment such as a cellular phone or a digital camera, the digital contents described in a markup language are often handled. However, the hardware resources are limited for the small portable equipment as mentioned above. Therefore, a rendering process of digital contents described in the markup language, especially the rendering process that draws the intermediate data already laid out becomes a large load on the hardware resources in the portable equipment. Accordingly, it is necessary to decrease the frequency at which the object is externally referenced, even for the object such as graphic or text that is relatively simply processed.
This invention has been achieved in the light of the above-mentioned circumstances, and it is an object of the invention to provide an image processing apparatus, an image processing method and a program that can decrease the frequency at which the object is externally referenced at the time of drawing and improve the drawing efficiency by suitably adjusting the bandwidth so that each element block of a structured document data may be included in one band.